Altough I agree with most of you, I still like torch down single ply. Incase you didn't know this, many of the companies that Ed has a preference to have been involved in MANY class action suits due to material failure. What do these companies do? They file chapter 11 and continue with a new name and a new "formula". I am currently bidding a Trocal roof that has failed at all the flashing details, (I'm adding pics.). When I attempted to help the owner with warranty issues I was told, "wait in line".
I have been doing torch for 20 years and have never had a material failure. A few install issues, but not material. YES, PVC and TPO are wonderfull to work with. But when you are running 35 guys with welders, who has time to, "pick" all their seams. With torch I can simply do my final walk visually and pick up install issues.
So call me old school, but after millions of dollars of torch decks with little or no problems for 20 years, I'll dance with who brought me here.